Which of the following compounds cannot be synthesized by the reaction of a Grignard reagent?

Identify the secondary alcohol from the following:

An alcohol $X$ $(C_4H_{10}O)$ on dehydration gives an alkene $(C_4H_8)$ as the major product,which on bromination followed by treatment with $Y$ gives an alkyne $C_4H_6$. The alkyne $C_4H_6$ does not react with sodium metal. What are $X$ and $Y$?

The major product of the following reaction is:

Identify the final product in the following reaction sequence: $CH \equiv CH$ $\xrightarrow[H_2SO_4]{HgSO_4}$ $\xrightarrow[H_2O]{CH_3MgBr}$ $\xrightarrow{P/Br_2}$

Describe the production,physical properties,physiological effects,and uses of methanol.